Composite polymeric tubes and pipes may be produced from any fiber and polymer matrix, most typically from glass and carbon fibre with a thermoplastic or thermosetting resin matrix. EP-A-0694726 discloses a method of forming an external groove on the end portion of a composite tube having a thermosetting resin matrix in which a split die is pressed into the external surface of the uncured pipe material on the mandrel to form a groove.
A method of forming the end portion of a thermoplastic tube in order to improve interconnections between tubes is shown in GB-A-928912.
The present invention provides a method of forming flanges and/or a groove in the external surface of a thermoplastic pipe or tube and in particular for a fibre reinforced thermoplastic composite pipe or tube.